By Mary Kekatos, Acting U.S. Health Editor for DailyMail.com
What are COVID-19 vaccine boosters?
A booster shot is given at least six months after people have been fully vaccinated against COVID-19.
It is meant to prolong immunity and give a 'boost' to the immune system to create higher levels of antibodies against the virus.
Is vaccine protection waning?
Not necessarily, although this topic is hotly debated.
Some people have weakened immune systems, either due to medical conditions or to age, that have left them unable to mount a full immune response to the first doses.
Some studies have found that vaccine protection does decrease after more than four months, which is common with several other immunizations.
However, health officials insist that vaccines are still highly effective against the most severe outcomes from COVID-19, including hospitalization and death.
Who is currently eligible?
Last month, boosters were authorized for Americans with compromised immune systems.
This week, the U.S. Food and Drug Administration (FDA) expanded that authorization to specific at-risk groups.
These include people aged 65 and older, long-term care facility residents and people aged 18 to 64 at high risk of severe COVID-19 due to underlying medical conditions.
Although the Centers for Disease
